Filling: Using a kitchen towel, squeeze off the excess liquid from the spinach. In a medium-sized bowl, mix together the spinach, feta, jalapenos, and yogurt. Set aside.

In a small bowl, mix together the milk and grits . Set aside.

In a large bowl, combine the onion, turkey , eggs, Worcestershire, parsley, stock, salt, pepper, and the grits. Mix until well combined. Transfer half of the mixture to the casserole dish and shape it into a medium-sized log. Using your fingers, make an indentation in the meat for the filling. This should resemble a canoe. Add the filling to the indentation and top with the remaining meat. Form the meatloaf , being sure to cover the filling completely with meat. Pour the tomato sauce over the meatloaf. Bake in the oven until the internal temperature registers 165 degrees F on an instant-read thermometer, about 55 to 60 minutes. Remove the meatloaf from the oven and let it rest for 10 minutes before slicing and serving.